Calipers



Patented July 6, 1925. i

" QUNITED; A

'::WILI3IAM L; menu or EIlMIRA, YNEW'YORK; s sIGNoR ToncnIPsn MAGmiIE Q-Iif' QMPANYQ-OInnlmmmnnwronmn ooitronnzpro w new 1:;

c i o m Pans", ,1

I n ilicano -aled namn 3, 1923. serial nolfsaas'zsf I This invention relatefsto geometrical in strum'ents for measuring distance, and particularly tojimproveme'nts i-n calipers-of the type. commonly employed fortakin'g inside? measurements.

Inside calipers of the type ordinarily used heretofore must be handled by skilled work men with extreme care when a high degree of-accuracy- :is desired? Thisv results from 9 'thefact that such';calipers ,must be placed 'ini contact with theisurface, or surfaces, of; the object having dimensions that are 'to be' measured, ins'uch a'manner that the imag- "inary line joining the two ends, or 7, measure ing polnts, of the-caliper legs oc'cuplesthe 1' same position relative to' saidr'surfacegat the every reading. If a reading be taken when this line .does' not occupy, said relative posi--,

tion, that is, ifthe calipers are canted, or inclined, the-result will b'e inaccurate.)

One-lo iethe-objects of this invention is to provide afpairof calipers,vof simple-and} rugged construction, which may be used by an unskilled: workman to quickly-obtain ac-*5. curate measurements of the kind indicated. Stated broadly, the"; invention comprises' a pair of calipers provided with means to assistan operative, at each reading,; in'plac-f,

ing the measuring points ofsaid calipers in the same position relative -to the surfaceof measuredr a The invention will be readily' understood by Ireferenceto the accompanying drawings, illustrating one embodiment of the inventive idea, wherein-- a v :Fig: 1 is a side elevation on airlof can-j pers embodying the present invention; a Fig.2 is a view-taken at right angles to Fig. 3 is a:viewillustrating my improved calipers-placed in contact with a surface to be measured, 1 -21 Q .5 :Referring to the" drawings, wherein like reference -numera ls refer 'toilikemparts throughout the several views, 4=andf5 are legs of an inside spring caliper having formed, any suitable mannerat the lower.

endsfthereof, the measuring-points 6 and 7, said legs being adapted to pivot about a double-headed pivot pin 8. The usual curved leaf spring 9, swivel heads 10, adjustlng screw 11,'and knurled nut 12, maintain legs 4 and 5 in'the proper position relative to pin 8, enablethe operative to adjust said points he object that-has the i dimension to j be tion to which they are set, as is 'well known;

When measuring the distanceapart of two points on a surface,,or onttwoisurfaces, itis desirable that points 6 and. I be placed in contact with said. surface orfsurfaces', ,in'such' a manner that the imaginary line joining.

substantially normal, toiithe surface at the pointsofcontact. .;My iin i proved calipers are,'accordingly,' provided] with means pivotally secured to legs 4c and 5 forfacilitating thepr per positioning of pointsgdandi'.

1 In "the form shown, cross-lever l i his preferably pivoted at its center 14 to legj5f at a Jpoint ,distantcfrom measuring pointy? 7 equal to the length'of: one arm of said 'rlevcr,

the-pointl4 being so. located relativeqto leg 5. that-it lies on astraightiline connecting point/57f and the center of pin 8 The inner," end of lever 13 ispivoted, in any suitable manner, as at 15,,tooneendof a link 16 the opposite end of ;said linkf beingpivoted;

to leg-Aatga point;.17 which islocatedat ar distance from the center of ping8 equal-to the length of one of the armsroflev'er l3, and on ja-sstraight line joining pointgdand thecenter;

of pin 8. Point'si14 andyl'5are positioned, onewith the other, in sucha'inanner-that a" straight line joining these ltwo p'oints,if extended, will pass. through thei'point 18 ,ajttheouter endof cr0ss-leverl13.-- It will now beseen that, the distance 14 515 equals the distance '8"j17, while length 15-17 equals 8 14, andit lines be ,drawn through the four points'8, 14', I5 and 17 a parallelogram. will beformed; Also, since the distances 68 and 78 are equal, and since the disk 5 tance -714 equals the distance j17-8 the distance from point-171m measuring point v 6 equals the-distance'15+'-17.

the outerriend of.cross-lever.--13, incontactwith the inner surface of said cylinder. Regardless'of the distance apart that points6 V "-Whenmeasuring the distance between two and 7 have been adjusted or moved, the V imaginary line joining thesepoints will now lie in a plane situated at right angles to the longitudinal axis ab of the cylinder being measured; .Th-is results fromthe faotth'at hoWever' compri-ses two isosceles triangles 15, 145 7 and-c7, 14', Iii-having theeominon I side illustrated bythe dottedline 7 14; and ,the base angles d, cl and c, c of said isosceles i Therefore;

1 triangles angle l5, 18; 7 This relatio" maybe expressed as follows l V I 2 4c +2 Ad=189;

,i romeo- I f It is now evident'thatgangle d plus angle-0 will always equal'QOZ and, since 617 +1'5 isan'isosceles triangle, it may be shoWn that points 6-15 andf? .will always lie on the I samestraight line, which line is always norworkman'in placin'gthe measuringpoints of cylinder} Inal to 'thei lon'gitudinal"axis oa -Tb of the embodying nie'ans ior assisting an unskilled the s ne-in the proper ineasurl ng position.

This greatlyfincreases thesp'eed and accujracy W1 '1 which readings may be obtained.-

' if 'le one ing' drawings with considerable particularay, it isjto be expressly understood that the drawings are for "purposes of illustration only and are not designed as a definition of the limits of the invention, reference being'j 7 had tothe appended claims for this purpose;

V WVhat is claimed is V 1 .;A deviceoi the class described com prisin -a pair of legs, means piyotally' con necting'said legs, a lever piv'ota'lly connected intermediate its'uen'ds to one. of said legs,

and a link pivoted to said lever and the other of said legs'wvhereby the free end of the lever and the measuring end of the adij'acent ealiper legs aremaintained'in: a line at right angles to a line througli' the measur-' ing points of said le'gs regardless of the dis tanee apart that the latter are adjusted 2; A device of'theclass described com- ;p-ri-sing a pair oflegs; a lever pivotally con' nected' to one-of sa c'l-legs, and means for inainta'finingfone end of saidlever and the measuring end of the caliper leg to which the lever is pivoted a line at right angles to the linepassingthrou ih the measuring points or said legs regardless of the distance apart that the latter are adjusted.

A deviceof -the class described coniprising a 1 pair of legs, means inluding a spring for pivotally' connecting said legs, a

form the angles of the large tri pivoted legs and one ofthe caliper legs,- a mounted intermediate its" end's'on sand 1 leg;

form of the invention has been described i and illustrated in the aoconip any;

lever pivotallyconnected to one of said legs, and means'tor malntaining one'end of said lever and the measuring end of the caliper support comprising a-measuring point on lever pivotally a link connecting said-lever tothe other of said caliper legs, said lever and link being f Such length a d so pivoted to" said legs and to each other that a line passing through the free end of said lever andithe' adjacent measuring point is substantially atv right angles to a; the measuring points of the caliper regard v 1 ,e less of the distance apart to vvhi-cl'r said; L'IhaVe thus provided alrim'provedcaliper points are adjusted. or 7 51A device; of the"- classi described com rising a pair oflegs, m'eans' pivotallly com. mating-said legs, mediate its" ends" to" one of said; legs;

other of said legs-"and to'one endof' the lever, and means for adjusting: said legs.

6. The combination: of an inside ealiper' and means attached thereto for preventlng cantifig" of the caliper measuring points line] passing through 3 lever pivotedintefi alink equal in length to' said lever pivoted-v to" the" whenfenga ed withan object.- tof-be'meas' ure'd, said means comprising jadisposed substantially in the plane ofthe caliper legs and" pi-votally mounted inter-' mediate its f ends on one of the vsame, the

nieasur'ingpoints of said leg' and: one end of said lever-being adapted to support the caliper on the interior of the object being measured, and a liIlkQGOH'DeOtlOIl for said cross-lever:

lever with the other caliper leg, said'lever 7 and link being of equal length.

7 In a device'of the "class described; the

combination of a pair ofadjustable caliper a 0 legs, a lever pivoted to one ofsaidl'legsga link pivot'ed' at one end to said lever and" at its opposite enditoithe other of said legs, and resilient me'ans'eng'aging each of. said legs, said lever and link being "sovpivote'd and of su'chlength' that the free-end' of: said lever and the adjacent measuring point are maintained in] a line meted substantially atright 'angles'te' a line passing through a r the measuring points of said. legs In testimony whereof I have signed; this speeiiication.

* L; Mesh-A1111; 

